ZAGREB, Croatia — Mikaela Shiffrin is living up to her billing as skiing’s next big star.

The 17-year-old captured a slalom by a massive 1.19-second margin Friday night, becoming the first American woman to win two World Cup races before turning 18. Her first career victory came last month in Sweden.

“Everything went really well today,” said Shiffrin, who had the fastest time in both runs. “It felt great.”

She leads the World Cup slalom standings and even overtook Lindsey Vonn as the top American in the overall standings.

Vonn resumed training Thursday after a monthlong break from the circuit but skipped this race. Shiffrin has 426 points overall to 414 for Vonn. Both are way behind leader Tina Maze of Slovenia, who has 1,139 points despite going out in the second run Friday.

“It’s definitely one of my goals to win the slalom title,” Shiffrin said. “And then the GS (giant slalom) title, and sometime the overall. Right now, I am taking it day by day and race by race.”

The overall crown might take some because Shiffrin competes only in the technical disciplines. But for now she is in the midst of a breakthrough season after becoming the youngest woman since 1977 to win two slalom races in one season. She also has six more top-10 finishes.

“I had a tricky time last year, a couple of races where I straddled (a gate),” Shiffrin said. “This year I fixed that and have found my groove.”

Shiffrin leads the slalom standings with 336 points, followed by Veronika Velez Zuzulova of Slovakia with 312 and Maze with 310.

Shiffrin led by nearly a half second after the first run and extended her advantage in the second, finishing in a combined 2 minutes, 1.73 seconds.

“I was just letting my skis taking me to the bottom, and that is what I am looking for,” she said.

She became the youngest winner in nine editions of the Zagreb event, which is billed as the Snow Queen Trophy. The winner is awarded a crown of glass and a robe. The crown, however, broke into pieces in a box.

“I think I have a new Halloween costume for next year,” Shiffrin said. “First I need to glue (the crown) back together.”

Shiffrin was helped by mistakes from her closest challengers after the opening leg — Maze and Sweden’s Maria Pietilae-Holmner, who both failed to finish their final run.

Frida Hansdotter of Sweden was second and Erin Mielzynski of Canada was 1.76 behind in third. The rest of the field finished more than two seconds behind Shiffrin.